1. Field of the Invention
The present invention relates to a locking device for an extension pipe of a vacuum cleaner.
2. Description of the Related Art
FIG. 1 shows a conventional vacuum cleaner. As shown in FIG. 1, the conventional vacuum cleaner includes a cleaner body 1 where main parts such as vacuum generating unit are mounted, a flexible hose assembly 10 connected to the cleaner body 1 and including an operation handle 11, a brush assembly 20 moving along a surface to be cleaned and having an extension pipe 21 connected to the operation handle 11, and an extension pipe locking device 30 for removably supporting the operation handle 11 and the extension pipe 21.
The extension pipe locking device 30 enables use of various auxiliary brushes (not shown) so that cleaning of various places such as recess of the room is enabled. More specifically, the extension pipe locking device 30 maintains connection of the brush assembly 20 or an auxiliary brush with the operation handle 11, while also enabling easy removal thereof.
FIG. 2 is a partial cutaway sectional view showing a conventional extension pipe locking device for a vacuum cleaner. As shown in FIG. 2, the conventional extension pipe locking device includes a holder 40, a locking member 50, an elastic member 60 and a cap 70.
The holder 40 is configured as a hollow pipe, with first and second connection parts 41, 42 formed at both ends thereof. The first and second connection parts 41, 42 are connected to the operation handle 11 and the extension pipe 21, respectively. The second connection part 42 of the holder 40 has a locking hole 42a formed in correspondence with a fixing hole 21a of the extension pipe 21.
The locking member 50 has a hook 51 which is protruded into the second connection part 42 through the locking hole 42a, and a button part 52 extended from the hook 51. The locking member 50 is pivotally disposed on the outer surface of the holder 40 to pivot on an axis 80. At a side of the hook 51 is formed an inclined surface 51a which is formed at a predetermined angle.
The elastic member 60 elastically bias the locking member 50 so that the locking member 50 can pivot counterclockwise with respect to the axis 80. Accordingly, the locking member 50 is maintained in the locked state, with the hook 51 being kept in an inserted state in the locking hole 42a. A compression coil spring is usually used for the elastic member 60.
The cap 70 is connected to the outer surface of the holder 40 to cover the elastic member 60 and the hook 51 and the axis 80 of the locking member 50. As a result, the respective parts are completely covered, and the recovery force of the elastic member 60 can be reinforced.
In the conventional locking device for an extension pipe of the vacuum cleaner constructed as above, with the button part 52 of the locking member 50 pressed in a state that the extension pipe is in locked state (see FIG. 2), the locking member 50 rotates about the axis 80 in the clockwise direction, and as a result, the hook 51 is unhooked from the fixing hole 21a of the extension pipe 21. Accordingly, the locking state is released, and the extension pipe 21 is separated.
After the separation of the extension pipe 21, because of the recovery force of the elastic member 60, the locking member 50 maintains an initial state, with the hook 51 being inserted in the locking hole 42a. Then as the extension pipe 21 is re-inserted to the second connection part 42 of the holder 40, the extension pipe 21 gets interfered with the hook 51, resulting the locking member 50 rotating about the axis 80 in the clockwise direction. As the extension pipe 21 is inserted to a position where the fixing hole 21a of the extension pipe 21 aligns with the locking hole 42a of the holder 40, the hook 51 is inserted in the fixing hole 21a through the locking hole 42a by the recovery force of the elastic member 60, locking the extension pipe 21. Meanwhile, the extension pipe 21 is smoothly inserted due to the presence of the inclined surface 51a of the hook 51.
However, according to the conventional locking device for an extension pipe of the vacuum cleaner, because there are the requirements for additional parts such as the locking member 50 having the hook 51 and the button part 52 integrally formed with the hook 51, and the elastic member 60 to return the locking member 50 to the initial position, the number of parts is increased, while assembling process also becomes complex. Accordingly, there was a need for an improvement.